T3 (Cytomel)

How It Works

The active thyroid hormone binds to nuclear thyroid receptors and changes the expression of metabolic genes. This regulates oxygen consumption, heat production and the turnover of carbohydrate, fat and protein. It acts directly without first requiring conversion from T4.

Metabolic Rate and Energy Turnover

The hormone sets the pace of many energy consuming cellular processes. Replacing a deficiency restores thyroid dependent metabolism towards normal. In a cutting context, interest centres on increased calorie expenditure, but ordinary replacement amounts do not produce weight reduction in people with normal thyroid function.

• Activating thyroid hormone receptors directly.
• Regulating resting energy expenditure and heat production.
• Restoring metabolic activity when too little active thyroid hormone is available.

Post Cycle Therapy

The hormone affects thyroid feedback rather than the testosterone axis, so steroid PCT does not address its recovery. TSH and thyroid hormone measurements are used to assess thyroid function after changes in exposure. Any continuing thyroid treatment depends on the underlying thyroid condition.

Side Effects

Excess thyroid hormone can cause rapid heartbeat, arrhythmias, anxiety, sweating, tremor, insomnia, diarrhoea and muscle loss. Sustained excess can reduce bone density and cause serious cardiovascular complications. Thyroid hormone is not an established weight loss treatment for people with normal thyroid function, and excessive amounts can be life threatening.